OSCP and F6 are two subunits of mitochondrial proton-ATPase. Each has been obtained pure. The sequence of F6 is almost completely known, that of OSCP is unknown. These two subunits of the proton-ATPase act together to bind the F1-sector of the enzyme (the ATP synthesis/hydrolysis catalytic unit) to the F0-sector (the proton channel in the membrane). In this research we will first define in molecular terms how F6 and OSCP achieve this binding. We shall next study whether F6 and OSCP themselves act as proton conductors between F0 and F1, and if this is so, the amino acids involved in proton transfer will be defined. Finally, transmittal of proton-gradient induced conformational change to F1 by OSCP and F6 will be studied. From the results we will be able to construct a detailed a molecular model of the mitochondrial proton-ATPase and make some choices between different plausible mechanisms of the coupling of H+-transport and ATP synthesis/hydrolysis.